1. Field of the Invention
The present invention generally relates to bonding apparatus, and more particularly, to an optical bonding apparatus, a touch sensitive display using the same and a method of making the same.
2. Description of the Related Art
A touch sensitive display includes a touch panel for sensing touch points and a display panel for displaying contents. The touch panel and the display panel are bonded together by optical bonding apparatus.
Usually, the conventional optical bonding apparatus is single-layer structure. When the touch sensitive display is illuminated through a backlight source , there may be color blocks appearing on the display panel, such color blocks present yellow if the display's background is white and present white if the display's background is gray. The phenomenon described above is named mura. Mura is a very common defect in electronic devices with LCD or the like, and it always decreases the contrast ratio, forms inhomogeneous areas and makes the edge of images blurry . When a color block caused by Mura covers an area larger than a pixel, it will affect the image quality and therefore a user will have difficulty viewing images on the display .
A bonding apparatus with multiple bonding layers is used for bonding the touch panel and the display panel to help solving the above problem. For example, a multi-layered bonding apparatus is a composition superposed between pressure sensitive bonding layers and thermal flow bonding layers. However, the multi-layered bonding apparatus has a problem of disassembly, that is, the bonded layers are hard to be disassembled from each other. If the touch panel or the display panel encounters problem, the difficulty of disassembly will lead to the difficulty of rework on the touch panel or the display panel. Disassembly will cause damage to the touch panel or the display panel.
Thus, it is desired to provide an optical bonding apparatus, a touch sensitive display and a method of making the optical bonding apparatus that overcomes the above drawbacks of the conventional touch panels.